PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 115 
many layers of calcarenite, limestone pebble conglomerate, and brown chert 
nodules. The formation attains a thickness of 108 feet in Cape Girardeau and 
Perry' Counties but thins to 75 feet at Kings Lake. Twenty-eight feet is exposed 
at Mineola, but there the Plattin has been eroded to this level. Few good col- 
lections were taken by Larsen from this formation, but he reports Cryptophrag- 
mus antiquatus (Raymond) among other fossils. Brachiopods listed are: 
Ancistrorhyncha sp. O. cf. O. wagneri (Okulitch) 
? Camerella sp. Opikina sp. 
Campylorthis deflecta (Conrad) *Parastrophina hemiplicata (Hall) 
Glyptorthis bellarugosa (Conrad) Rostricellula sp. 
Opikina subtriangularis Wilson 
Correlation is suggested with the Witten of the Appalachians and Platteville 
of the upper Mississippi Valley. 
Hager formation.—Generally fine-textured limestone named after Hager 
School in Perry County. Three facies are recognizable: The major part is 
slabby olive-gray limestone with buff-weathering partings; calcilutite and cal- 
carenite make up the remainder. The first facies is mainly in the thicker sec- 
tions on the south. The calcilutite generally overlies the slabby limestone and 
both grade laterally into calcarenite. The formation is 85 to 93 feet thick in Cape 
Girardeau County and thins out near the latitude of St. Louis. The slabby lime- 
stone facies contains abundant fossils: 
Campylorthis deflecta (Conrad) ? R,. minnesotensis (Sardeson) 
*Glyptorthis bellarugosa (Conrad) ? Rostricellula sp. 
*Hesperorthis tricenaria (Conrad) Strophomena cf. S. delicatula Fenton 
*Opikina cf. O. transitionalis (Okulitch) S. dignata Fenton 
*O. cf. O. wagneri (Okulitch) S. extgua Fenton 
Opikina sp. S. plattinensis Fenton 
Orbiculoidea sp. Strophomena sp. 
Rostricellula cuneiformis (Fenton and Fenton) Zygospira recurvirostris (Hall) 
Correlation of Hager formation.—Presence of Campylorthis is a link to the 
Platteville limestone of the upper Mississippi Valley. The formation is also 
linked to the Lebanon of the Central Basin of Tennessee by the Zygospira. 
Macy formation.—Named after Macy in Ste. Genevieve County, Mo. The 
formation is 87 feet thick at the type locality and is slightly thicker in Cape 
Girardeau County. It thins to a little more than 4o feet in Lincoln County but 
is absent in Callaway County to the west. The formation is mostly of fine-tex- 
tured limestone divided into two members: Hook below and Zell above. 
Hook member of Macy formation——This member is composed of fine, yel- 
lowish-brown fucoidal limestone with irregular buff-weathering dolomitic part- 
ings. The member is 13 to 15 feet thick near Kings Lake in Lincoln County, Mo., 
and thickens to 4o feet in Perry County. The following brachiopods are reported: 
Campylorthis deflecta (Conrad) 
Hesperorthis tricenaria (Conrad) 
Opikina sp. 
